Deaetutgl device



Jan. '10, 1928.

J. L. WEST 'DRAFIING nsvxcs Filed July 19. 1926 INVENTOR. JESSE L. Wrgsw ATTORNEY hatented Jan. lid, W28.

JESSE L. WEST, OF SAN DIEGO, CALIFORNIA.

DRAFTING nnvron.

Application filed Jufy 19,

iMy invention relates to drafting devices, more particularly to such devices commonly known as T squares. I

The objects of my invention are: first, to provide'a device of this class in which the head normally placed'against the left hand edge of a drawing board may be easily and quickly adjusted to any angle desired relative to the straight edge or blade thereof and rigidly secured relative to the straight edge or blade with a minimum of effort; second, to provide a device of this class having a protractor on the head around the pivotal connection thereof with the straight edge member whereby said straight edge member may be easily shifted to any desired angle relativeto the head, said protractor being positioned outside of or to the left of the bearing edge of the head so that the same will not interfere in any way with the drafting operations; third, to provide a drafting device of this class in which the protractor portion of the head and an extended portion of the straight edge member provide a corn venient grip or handle for manipulating the device on a drawing board; fourth, to-

provide novel means in connection with the pivot bolt or axis of the pivotal connection between the headand the straight edge mem? her for rigidly securing thesame together in certain shifted positions, the clamp, or lock means being positioned underneath the head and out of the way and adjacent the pivotal axis, permitting the outer portion of the head to be made of relatively light construction; fifth, to provide a device of this class having a straight edge member which may be readily extended or secured in compact or short length,as desired; sixth, to provide as a whole a novelly constructed drafting device, and seventh, to provide a device of this class which is simple and economical of construction proportionate to its functions, durable, accurate and which will not readily deteriorate or get out of order.

lVith these and other objects in view, as

will appear hereinafter, my invention con sists of certain novel features of construction, combination and arrangement of parts and portions, as will be hereinafter described in detail and particularly set forth in the appended claims, reference being had to the accompanying drawings and to the characters er reference thereon, which form a par of this application, in' which:

Figure l is atop view of my drafting deing board or the like.

was. Serial No. 123,401.

from'the head end of the device, and Fig. 4 1

is a fragmentary side elevational view thereof. Y

Like characters of reference refer to similar parts throughout the several views of the drawings. i

The. head member 1 is of angular crosssection and is preferably made of heavy gage sheet metal formed into such section. The

outer side of the flange 1 of the head memher 1 serves as the bearing edge or surface adapted to engage with one edge of a draw- The portion intermediate the ends of the other flange of the head, member 1 is wide and the portions extending'therefrom tos wards the ends of the head member are rela tively narrow, as shown best in Figs. 1 and 4;. To the wide portion intermediate the ends, of'the upper flange is secured a pro-- tractor 2 by means of rivets or other suitable means 3. This protractor is positioned atjthe upper side of the head member and extends tothe left of the bearing surface of the head member and does not interfere, with the drawing operation for which the device may be used.

' Atthe central portion of the protractor 2 is'provided an elongated opening 2, which extends transversely of the longitudinal extent of the head member 1. In the wide portion atthe upper side of the head member 1 is also provided an elongated opening 1", I

which registers with the opening 2. Throughsaid openings 2 and 1 extends the flattened portione 'of the shank 4 of the pivot'member 4. Between the large head P of the pivot member and the protractor 2 is positioned the one end ofthe' straightedge I "member or blade 5, which is provided with a circular opening whichis spaced a slight distance from said end and through which the'round portion of the shank d directly below the head at of the pivot member, extends. Between the under side of the straightedge member 5 and the upper side of the protractor 2 and around the shank of the pivot member is positioned a washer 6, which spaces said members apart. Said washer is preferably secured to the protractor and head member 1 by means of plurality of rivets 7.

The flat-portion 4L ofthe shank of the pivot member is provided through its flat sides with a longitudinal slot t which extends to near the lower end of said fiat portion and is provided at the lower end of the slot with a knife or hearing edge 4;, as shown best in Figs.- 2 and 3. Through the slot 4 is positioned the loose clamping lever 8, which is of flat construction and provided at its lower edge and intermediate its ends with a transverse, t -shaped groove 8, which is adapted to receive the knife edge 4 of the pivot member and position the clamping member 8 relative thereto and to the head member. The one end of the lever 8 engages the under side of the wide port-ion of the head member underneath the protractor. At the opposite end of the lever 8 is provided a thumbscrew 9, which is also adapted to engage the under side of the wide portion of the head member for forcing the shank of the pivot member downwardly and clamping the straightedge member 5 relative to the head member.

The short end of the straight-edge member extending normally over the graduations of the protractor is bifurcated, as indicated by 5*, to permit the graduations and degrees of the protractor to be seen therethrough. Over the opening made by the bifurcated portion and preferably at the under side of the straight-edge member is secured, in any suitable manner, a hair-line member 10, which is provided at its median line and preferably at its under side with a hair-line or arrow for designating the angularity of the straightedge member relative to the head member.

At the opposite edges of the straight-edge member 5, which is preferably made of metal, are-provided strips of transparent material 5", such as celluloid, the ends of said strips 5 at the head end of the straight-edge member being protected by lugs 5 of metal extending outwardly from the main portions of the straight-edge member or blade, as shown in Fig. 1. e

The straight-edge member 5 is preferably made short for convenience in handling and packing, but may be extended by the exten-' sion straight-edge member 11, which is. con+ structed the same and of the same cross-secside of the member llat the end adapted to be abutted againstthe end of the member 5 is secured a connecting member or plate 12 by means of rivets 13. Said plate, when'in position to extend the straightedge, rests with its opposite end at the upper side of the member .5. The portion of the plate 12 extending beyond the extension member 11 is provided with a transverse slot 12 through which is adapted to extend a screw member 15 secured near the end of and extending upwardly from the member 5. On the screw member 15 is a thumbnut 16, which is adapted to secure the plate 12 against the straightedge member 5. At the opposite sides of the slot 12 of the plate 12 and preferably at the median line of said plate are provided holes 12 which are adapted to receive pins or lugs 1 f positioned at the opposite sides of the screw member 15 and also on the median line of the straight-edge member 5 for fixedly positioning the extension member 11 relative to the member 5.

it the opposite end of the extension member 11 is provided a longitudinal slot 11 at the median line thereof, which is adapted to receive the screw member 15. 111 line with the slot 11" is a hole 11 adapted to receive the stud or pin 14 positioned between the screw member 15 and the head end of the straight-edge member 5. In order to reduce the length of the straight-edge of the T square after the same is extended, the thumbnnt 1G is unscrewed slightly, the member 11 lifted upwardly so that the plate 12 clears the pinsll and the same is then shifted forwardly. The member 11 is then placed with the slotted portion 11 around the screw member 15 and with the one pin 14 in the hole 11", as shown by dotted lines in Fig. 1.

Though I have shown and described a particular construction, combination and arrangement of parts, I do not wish to be limited to this particular construction, combination and arrangement, but desire .to include in the scopeof my invention the construction, combination and arrangement sub stantially as set forth in the appended claims.

Having thus described my invention, what 1 claim as new and desire to secure by Let.- ters Patent is: i 1. In a drafting device of the class described, 21 head member having a bearing surface one side and a protractor at its upper side and extending outwardly only from said bearing surface, a straight-edge member pivotally mounted on and at the upper side of said head member with its one end extending from its pivotal axis toward and beyond said bearing surface and the other end extending over said protractor and. provided with a hair-line adapted to register with the graduations on said protractor, a pivot member extending from the upper'side of said straightedge member through said head member at the central portion of the protractor, a clamp lever extending through'the end of the pivot member extending below said head member 

